Answer:
c) it appears to be sound because the data are not biased in anyway.
Step-by-step explanation:
From the information given regarding the sample selection method , the size, the larger sample from which the survey subject were selected, we can conclude that the data is sound and not in anyway biased. The subject were selected from a reputable market research firm, which means the subjects were chosen from a larger sample which is reliable and not just a voluntary pool of subjects. Also, the selection process is randomized. Based on these, there are no flaws which are likely to cause the introduction of bias into the sample selected. Hence, the data is sound and not in any way biased.
Answer:
The right answer is:
a.H0: μd = 0; H1: μd > 0
Step-by-step explanation:
The claim that want to be tested is that the sales were significantly increased after the commercial, indicanting that the advertisement campaign was effective.
This claim is usually expressed in the alternative hypothesis as it has to have enough evidence to prove that it is true.
Then, the alternative hypothesis H1 should state that the difference (sales after - sales before) is higher than 0.
The null hypothesis would state that the difference is not significantly different from 0, or, in other words, that the sales are the same before and after and that the variation is due to pure chance.
Then, the null hypothesis H0 would state that the difference is equal to 0.
The right answer is:
a.H0: μd = 0; H1: μd > 0
Answer:
D. No, because the sample size is large enough.
Step-by-step explanation:
The central limit theorem states that "if we have a population with mean μ and standard deviation σ and take sufficiently large random samples from the population with replacement, then the distribution of the sample means will be approximately normally distributed. This will hold true regardless of whether the source population is normal or skewed, provided the sample size is sufficiently large".
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
If the sample size is higher than 30, on this case the answer would be:
D. No, because the sample size is large enough.
And the reason is given by The Central Limit Theorem since states if the individual distribution is normal then the sampling distribution for the sample mean is also normal.
From the central limit theorem we know that the distribution for the sample mean 
is given by:
If the sample size it's not large enough n<30, on that case the distribution would be not normal.
Answer:
AH = 
Step-by-step explanation:
The opposite sides of a rectangle are congruent , so
GH = RA = 7
Using Pythagoras' identity in right Δ GHA
AH² + GH² = GA²
AH² + 7² = 10²
AH² + 49 = 100 ( subtract 49 from both sides )
AH² = 51 ( take the square root of both sides )
AH = ≈ 7.14 ( to 2 dec. places )
Answer:
Width of the rectangle = 7 meters
Length of the rectangle = 12 meters
Step-by-step explanation:
Perimeter of a rectangle = 2(length + width)
Perimeter of the rectangle = 38 meters
Width of the rectangle = w
Length of the rectangle = w + 5
Perimeter of a rectangle = 2(length + width)
38 = 2{(w + 5) + w}
38 = 2(w + 5 + w)
38 = 2(2w + 5)
38 = 4w + 10
38 - 10 = 4w
28 = 4w
w = 28/4
w = 7 meters
Width of the rectangle = w
= 7 meters
Length of the rectangle = w + 5
= 7 + 5
= 12 meters
